package arithmetic;

import java.util.Scanner;

/**
 * @program: javaLearn
 * @description: 寻找只有一个数的个数是奇数（异或运算）
 * @author: renhai
 * @Date ：2022/3/1 22:56
 **/
public class LookingOdd {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String nums = scanner.nextLine();
        int len = nums.split(" ").length;
        int eor = 0;
        for (int i = 0; i < len; i++) {
            eor = eor ^ Integer.parseInt(nums.split(" ")[i]);//异或运算求出奇数个数的数
        }
        System.out.println(eor);
    }
}
